SEATAC, Wash. -- A "suicidal" airline mechanic stole an empty Alaska Airlines plane and took off from Sea-Tac International Airport in Washington state before crashing near a small island Friday night, officials said.

Preliminary information suggests that the 29-year-old mechanic stole the Horizon Air Q400 and the crash occurred because the person was "doing stunts in air or lack of flying skills," the Pierce County Sheriff's Department said.

Witnesses reported seeing the plane being chased by military aircraft before it crashed near Ketron Island, southwest of Tacoma, Washington. There were no passengers aboard.

A video posted Friday night by a resident of Washington showed what was described as the plane being chased by a fighter jet.

We've confirmed a Horizon Air Q400 that had an unauthorized takeoff from SeaTac around 8pm has gone down near Ketron Island in Pierce County, WA. We're working to confirm who was on board, we believe there were no guests or crew on board other than the person operating the plane.